Chip impalement spears for rotary cutters

Abstract

Chip-impalement spears for rotary cutters are provided in a rectangular shape with a single sharp bevelled edge along the top of the spears and adapted to be placed parallel to a roller of the rotary cutter. The spears are embedded in one roller and arranged so that their sharp edges will come into slight contact with an opposing roller. Properties of the spears, in particular, hardness, are selected to enable the spears to be rapidly bent over in use, forming a chip-retaining barb. Spears having this capability may be obtained by making transverse cuts across a cutting rule.

We claim: 
     
       1. A chip-impalement spear for a rotary cutter having a pair of opposing rollers comprising: a metal body adapted to have one end thereof secured within the surface of a roller, the opposite end having a generally rectangular cross section with a single bevelled, straight, sharp edge along the opposite end and adapted to be placed with the said edge parallel to the roller and positioned so that the edge will come into slight contact with an opposing roller; and   said metal body being elastically deformable such that said edge elastically deforms into a barb upon making contact with said opposing roller.   
     
     
       2. A chip-impalement spear as defined in claim 1 wherein said metal body has a scleroscopic temper hardness of 35 to 85. 
     
     
       3. A chip-impalement spear as defined in claim 2 wherein said metal body has an overall rectangular cross section. 
     
     
       4. A chip-impalement spear as defined in claim 2 wherein said metal body is made of A.I.S.I. 1065 steel. 
     
     
       5. A chip-impalement spear as defined in claim 3 wherein said metal body has a width of 1/32 to 1/2 inch and a thickness of 1/64 to 1/8 inch. 
     
     
       6. A chip-impalement spear as defined in claim 5 wherein said edge is bevelled at an angle of 30° to 75°. 
     
     
       7. In combination, a rotary cutter including at least one pair of cooperating rollers having mounted thereon a plurality of protruding knives arranged to make transverse cuts across a web of material being fed through in a manner such as to produce chips of said material; a plurality of generally rectangular spears embedded in at least one of said rollers and arranged to impale said chips upon making said cuts; and   said spears having a single sharp bevelled edge at their protruding ends parallel to said knives and being placed so that said edge will come into slight contact with an opposing roller upon rotation of said rollers, such that said edge elastically deforms into a chip-retaining barb at the protruding end of the spears.   
     
     
       8. The combination as defined in claim 7 wherein said spears are located so that 0.005 inch of the sharp-edged ends of said spears will come into contact with an opposing roller. 
     
     
       9. The combination as defined in claim 7 wherein each said spear is mounted with said edge disposed forward with respect to the direction of the roller in which the spear is embedded.